JP2012177095A - Adhesive and adhesive tape - Google Patents

Abstract

A pressure-sensitive adhesive capable of forming a pressure-sensitive adhesive layer excellent in anchoring property with a substrate is provided.
A pressure-sensitive adhesive containing a polyolefin (a), a hydroxyl group-containing polyolefin (b), and a crosslinking agent (c) having a functional group capable of reacting with a hydroxyl group. The adhesive whose cross-linking agent (c) is isocyanate. The adhesive whose content of a crosslinking agent (c) is 0.01-150 weight part with respect to 100 weight part of polyolefin (a). The adhesive whose A value in following formula (I) is 0.25-14250. A = hydroxyl value of hydroxyl group-containing polyolefin (b) (mgKOH / g) × number of parts by weight of hydroxyl group-containing polyolefin (b) with respect to 100 parts by weight of polyolefin (a) (I)
[Selection figure] None

Description

  The present invention relates to a polyolefin-based pressure-sensitive adhesive containing polyolefin, and a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive.

  Polyolefin pressure-sensitive adhesives (particularly rubber-based pressure-sensitive adhesives containing rubber such as polyisobutylene) are used in various applications. However, it is known that polyolefin pressure-sensitive adhesives and rubber-based pressure-sensitive adhesives have poor adhesion to general substrates (for example, polyester substrates or polyolefin substrates) (hereinafter referred to as “adhesiveness to substrates”). May be abbreviated as “throwing ability”). Therefore, various techniques for improving the anchoring property of the pressure-sensitive adhesive layer formed from the polyolefin-based pressure-sensitive adhesive have been proposed so far.

  For example, Patent Document 1 discloses that an undercoat layer is provided between a rubber-based pressure-sensitive adhesive layer and a substrate (support) in order to improve anchoring properties. However, providing an undercoat layer is not preferable because it requires a process and equipment for that purpose.

JP-A-4-370179

  The present invention has been made paying attention to the above-described circumstances, and an object thereof is to provide a pressure-sensitive adhesive capable of forming a pressure-sensitive adhesive layer excellent in anchoring properties with a substrate.

  As a result of extensive studies by the present inventors, it has been found that the above object can be achieved by incorporating a polyolefin-based pressure-sensitive adhesive with a hydroxyl group-containing polyolefin and a crosslinking agent having a functional group capable of reacting with a hydroxyl group. The present invention based on this finding is as follows.

[1] A pressure-sensitive adhesive containing a polyolefin (a), a hydroxyl group-containing polyolefin (b), and a crosslinking agent (c) having a functional group capable of reacting with a hydroxyl group.
[2] The pressure-sensitive adhesive according to [1], wherein the crosslinking agent (c) is an isocyanate.
[3] The pressure-sensitive adhesive according to [1] or [2], wherein the content of the crosslinking agent (c) is 0.01 to 150 parts by weight with respect to 100 parts by weight of the polyolefin (a).
[4] The pressure-sensitive adhesive according to any one of [1] to [3], wherein the A value in the following formula (I) is 0.25 to 14250.
A = hydroxyl value of the hydroxyl group-containing polyolefin (b) (mgKOH / g) × number of parts by weight of the hydroxyl group-containing polyolefin (b) with respect to 100 parts by weight of the polyolefin (a) (I)
[5] The polyolefin (a) according to any one of the above [1] to [4], wherein the polyolefin (a) is a polymer having a structural unit derived from at least one selected from the group consisting of propylene, butene, hexene and octene. Adhesive.
[6] An adhesive tape having a substrate and an adhesive layer,
The adhesive tape which has the adhesive layer formed from the adhesive as described in any one of said [1]-[5] on the at least single side | surface of a base material.
[7] The pressure-sensitive adhesive tape according to [6], wherein the pressure-sensitive adhesive layer has a thickness of 1 to 100 μm.

  If the adhesive of this invention is used, the adhesive layer excellent in anchoring property with a base material can be formed.

It is the schematic which shows the method of peeling the adhesive layer and base material of an adhesive tape in evaluation of the anchoring property of the adhesive tape prepared in the Example and the comparative example.

1. Adhesive The adhesive of the present invention contains a polyolefin (a), a hydroxyl group-containing polyolefin (b), and a crosslinking agent (c). Hereinafter, each of these components will be described in order.

[Polyolefin (a)]
The pressure-sensitive adhesive of the present invention contains one or more polyolefins (a). In the present invention, “polyolefin” means a polymer having a structural unit derived from an olefin. In the present invention, the “olefin” also includes aromatic vinyl compounds such as styrene. Furthermore, in the present invention, “polymer” refers to both homopolymers and copolymers. Any polyolefin (a) can be used as long as it can be dissolved in an organic solvent together with other components and applied to a substrate.

  Examples of the polyolefin (a) include α-olefin homopolymers formed from one monomer selected from the group consisting of ethylene, propylene and α-olefins having 4 to 20 carbon atoms. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1 -Heptene, 1-octene, 1-decene, 1-dodecene and the like. The α-olefin homopolymer is preferably a propylene homopolymer (narrowly defined polypropylene). Examples of the propylene homopolymer include amorphous polypropylene and the like.

  Examples of the polyolefin (a) include an α-olefin copolymer formed from at least two monomers selected from the group consisting of ethylene, propylene, and an α-olefin having 4 to 20 carbon atoms. . Among these, a copolymer having ethylene as a main monomer (that is, an ethylene-based α-olefin copolymer) and a copolymer having propylene as a main monomer (that is, a propylene-based α-olefin copolymer). Coalescence) is preferred. The α-olefin copolymer may be a random copolymer, a block copolymer, or a graft copolymer.

  The ethylene structural unit amount of the ethylene-based α-olefin copolymer is, for example, 50 to 95 mol%, preferably 70 to 95 mol%. The α-olefin structural unit contained in the ethylene-based α-olefin copolymer is one formed from at least one monomer selected from the group consisting of 1-butene, propylene, 1-hexene and 1-octene. preferable. Particularly preferred ethylene-based α-olefin copolymers include ethylene-1-butene copolymers and ethylene-propylene copolymers. Such an ethylene-1-butene copolymer may contain a structural unit derived from an α-olefin other than ethylene and 1-butene in an amount of 10 mol% or less. Similarly, the ethylene-propylene copolymer may contain a structural unit derived from an α-olefin other than ethylene and propylene in an amount of 10 mol% or less. Such a copolymer is produced, for example, by copolymerizing ethylene and α-olefin using a catalyst comprising a transition metal catalyst component (for example, vanadium compound or zirconium compound) and an organoaluminum compound catalyst component. be able to.

  The propylene structural unit amount of the propylene-based α-olefin copolymer is, for example, more than 50 mol% and 95 mol% or less, preferably 70 to 95 mol%. Further, the α-olefin structural unit contained in the propylene-based α-olefin copolymer is formed of at least one monomer selected from the group consisting of ethylene, 1-butene, 1-hexene and 1-octene. Those are preferred. A particularly preferred propylene-based α-olefin copolymer is a propylene-ethylene random copolymer. In addition, this propylene-ethylene random copolymer may contain the structural unit derived from alpha olefins other than propylene and ethylene in the quantity of 10 mol% or less. The propylene-based α-olefin copolymer can be produced using a metallocene-based catalyst, as described in, for example, JP-A-2000-191862.

  A commercially available product can be used as the α-olefin copolymer. Examples of commercially available ethylene-based α-olefin copolymers include Tuffmer P series, Tuffmer A series (all manufactured by Mitsui Chemicals), and Engage (made by Dow Chemical Co.). Moreover, as a commercial item of a propylene-type alpha-olefin copolymer, Toughmer XM series (made by Mitsui Chemicals) etc. are mentioned, for example.

  Polymethylpentene can also be used as the polyolefin (a). Examples of polymethylpentene include a homopolymer of 4-methyl-1-pentene, and a copolymer of 4-methyl-1-pentene and other α-olefins. The amount of 4-methyl-1-pentene constituent unit in the polymethylpentene copolymer is preferably 50 to 95 mol%, more preferably 70 to 95 mol%. The polymethylpentene may be a crystalline polymer. Examples of the α-olefin structural unit in the polymethylpentene copolymer include 2 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene and 1-octadecene. Those derived from? -20 olefins are preferred. Among these, 1-decene, 1-tetradecene, and 1-octadecene exhibiting good copolymerizability with 4-methyl-1-pentene are more preferable. Examples of commercially available products of polymethylpentene include TPX-S (4-methylpentene-1-α-olefin copolymer, manufactured by Mitsui Chemicals).

  As long as it dissolves in an organic solvent, diene rubbers such as polyisoprene and polybutadiene can also be used as the polyolefin (a). As such polyisoprene, those having a cis-1,4 bond of 90% or more and a Mooney viscosity (ML1 + 4 at 100 ° C.) of 40 to 70 are preferable. Examples of commercially available products of polyisoprene include IR-307 and IR-310 (manufactured by Kraton Polymer Co., Ltd.). As the polybutadiene, those having a cis-1,4 bond of 90% or more and a Mooney viscosity (ML1 + 4 at 100 ° C.) of 25 to 50 are preferable. Examples of commercially available products of polybutadiene include Nipol BR1220, Nipol BR1220L (manufactured by Nippon Zeon), and BR01 (manufactured by JSR).

  The polyolefin (a) includes, for example, a block A mainly containing a structural unit derived from an aromatic vinyl compound (hereinafter sometimes abbreviated as “aromatic vinyl compound unit”), and isoprene. A block comprising a structural unit derived (hereinafter sometimes abbreviated as “isoprene unit”) and a structural unit derived from 1,3-butadiene (hereinafter sometimes abbreviated as “1,3-butadiene unit”). A hydrogenated block copolymer consisting of B (hereinafter sometimes referred to as “hydrogenated TPE”).

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, t-butylstyrene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, divinylbenzene, vinylpyridine and the like can be mentioned. These may use only 1 type and may use 2 or more types together. Moreover, when using 2 or more types of aromatic vinyl compounds, they may form the block structure in the block A, and may form the random structure.

  The block A mainly contains aromatic vinyl compound units, but may contain structural units derived from diene hydrocarbons such as isoprene and butadiene. The amount of structural units derived from these diene hydrocarbons is preferably 20% by weight or less in the block A. When this amount exceeds 20% by weight, a phenomenon in which a part or all of the pressure-sensitive adhesive layer remains on the adherend (so-called adhesive residue) occurs when the adhesive tape is peeled off from the adherend due to a decrease in cohesive force. It tends to be easier. These diene hydrocarbons may form a block structure in the block A or a random structure.

  Block B consists of isoprene units and 1,3-butadiene units. The polymerization form of isoprene and 1,3-butadiene may be random copolymerization, block copolymerization or tapered block copolymerization. Further, the ethylenic double bond of the isoprene unit and the 1,3-butadiene unit is hydrogenated (hydrogenated), and the hydrogenation rate is preferably 90% or more. This hydrogenation rate is more preferably 95% or more, and still more preferably 97% or more. When the hydrogenation rate is less than 90%, the weather resistance of the pressure-sensitive adhesive layer is lowered, and adhesive residue tends to be generated on the adherend during peeling.

  A commercially available product can be used as the hydrogenated TPE. As a commercially available product of hydrogenated TPE, for example, Septon 4030 manufactured by Kuraray Co., Ltd. (hydrogenated product of block copolymer of styrene / 1,3-butadiene-isoprene / styrene, styrene constitutional unit amount in copolymer: 13 % By weight of 1,3-butadiene-isoprene block: 45% by weight) and Septon 4033 (hydrogenated block copolymer of styrene / 1,3-butadiene-isoprene / styrene) Styrene structural unit amount in the copolymer: 30% by weight, 1,3-butadiene structural unit amount in the 1,3-butadiene-isoprene block: 50% by weight) and the like.

  Moreover, you may use a styrene-type thermoplastic elastomer as polyolefin (a). Examples of the styrene thermoplastic elastomer include styrene AB type diblock copolymers (diblock) such as styrene / butadiene copolymer (SB), styrene / isoprene copolymer (SI), and styrene / butylene copolymer. Styrene-butadiene block copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-butylene-styrene copolymer such as styrene-butylene-styrene copolymer (triblock) Copolymer); Styrenic ABAB type block copolymer (tetrablock copolymer) such as styrene / butadiene / styrene / butadiene copolymer (SBSB), styrene / isoprene / styrene / isoprene copolymer (SISI); Styrene / butadiene / styrene / butadiene / styrene copolymer SBSBS), styrene-based ABABA block copolymers (pentablock copolymers) such as styrene / isoprene / styrene / isoprene / styrene copolymers (SISIS); multi-block copolymers having more than these structural units; styrene Butadiene copolymer; styrene / isoprene random copolymer; and the like.

  As the styrenic thermoplastic elastomer, it is preferable to use a hydrogenated ethylenic double bond from the viewpoint of weather resistance. Examples of such hydrogenated products include hydrogenated products of AB type diblock copolymers such as styrene / ethylene-butylene copolymer (SEB) and styrene / ethylene-propylene copolymer (SEP); ABA type such as ethylene-butylene copolymer / styrene (SEBS), styrene / ethylene-propylene copolymer / styrene (SEPS), styrene / ethylene-butylene copolymer / styrene / ethylene-butylene copolymer (SEBSEB), etc. A hydrogenated product of a triblock copolymer or an ABAB-type tetrablock copolymer; a styrene / ethylene-butylene random copolymer (HSBR); and the like.

  Also, as the styrene thermoplastic elastomer, styrene random copolymers such as styrene / butadiene rubber (SBR), ABC type styrene / olefin crystals such as styrene / ethylene-butylene copolymer / olefin crystals (SEBC), etc. Block copolymers; and hydrogenated products thereof.

  When a mixture of hydrogenated TPE and styrenic thermoplastic elastomer is used as polyolefin (a), the content of styrenic thermoplastic elastomer is preferably 50% by weight in the total of hydrogenated TPE and styrenic thermoplastic elastomer. Hereinafter, it is more preferably 30% by weight or less. If this content is 50% by weight or less, the adhesive residue on the adherend can be sufficiently suppressed.

  Examples of the polyolefin (a) include isobutylene polymers. The isobutylene polymer may be either an isobutylene homopolymer or an isobutylene copolymer (that is, a copolymer of isobutylene and another monomer). The structural unit amount derived from isobutylene in the isobutylene copolymer is preferably 50% by weight or more. Examples of the isobutylene copolymer include random copolymers of isobutylene and normal butylene, copolymers of isobutylene and isoprene (regular butyl rubber, chlorinated butyl rubber, brominated butyl rubber, partially cross-linked butyl rubber, etc.), and additions thereof. Examples thereof include a sulfate and a modified product. As the isobutylene polymer, polyisobutylene which is a homopolymer is preferable.

  The polyolefin (a) is preferably a polymer having a structural unit derived from at least one selected from the group consisting of propylene, butene (also referred to as butylene), hexene and octene (hereinafter referred to as “polyolefin (a-1)”). ). The butene, hexene and octene may be either linear or branched. Further, the polyolefin (a-1) may be either a homopolymer or a copolymer. Examples of the polyolefin (a-1) include the above-mentioned propylene homopolymer (polypropylene in a narrow sense), propylene-based α-olefin copolymer, hydrogenated TPE, and isobutylene-based polymer. Among these, propylene homopolymer (polypropylene), hydrogenated TPE, and isobutylene-based polymer are preferable, and propylene homopolymer (polypropylene) and polyisobutylene are more preferable.

  The number average molecular weight (Mn) of the polyolefin (a) is preferably 3,000 to 1,000,000, more preferably 4,000 to 800,000. When the number average molecular weight is less than 3,000, the cohesive force may be reduced and the adhesive may remain on the adherend. On the other hand, when the number average molecular weight exceeds 1,000,000, the adhesive force is lowered and desired. The adhesive strength of may not be obtained.

  The content of the polyolefin (a) in the pressure-sensitive adhesive is preferably 10 to 99.95% by weight, more preferably 20 to 99.5% by weight. When this content is less than 10% by weight, the adhesive strength is lowered, and the desired adhesive strength may not be obtained. On the other hand, when it exceeds 99.95% by weight, the adhesion to the substrate is deteriorated. There is a case. In addition, the amount of the organic solvent is not included in the “adhesive” which is the standard for the content.

[Hydroxyl-containing polyolefin (b)]
The pressure-sensitive adhesive of the present invention contains one type or two or more types of hydroxyl group-containing polyolefin (b). The hydroxyl group-containing polyolefin (b) is used for reacting with the crosslinking agent (c) during the formation of the pressure-sensitive adhesive layer. As the hydroxyl group-containing polyolefin (b), those having good compatibility with the polyolefin are preferable.

  The number average molecular weight (Mn) of the hydroxyl group-containing polyolefin (b) is preferably 500 to 500,000, more preferably 1,000 to 200,000, and still more preferably 1,200 to 150,000. When the number average molecular weight of the hydroxyl group-containing polyolefin (b) exceeds 500,000, the solubility in the crosslinking agent (c) is low, and therefore the layer mainly composed of the crosslinking agent (c) in the pressure-sensitive adhesive layer (that is, polyolefin) Most of the hydroxyl group-containing polyolefin (b) is dissolved in the layer mainly composed of the polyolefin (a) and hardly reacts with the crosslinking agent (c). As a result, it may be difficult to obtain sufficient throwing performance. On the other hand, when the number average molecular weight of the hydroxyl group-containing polyolefin (b) is less than 500, the hydroxyl group-containing polyolefin (b) tends to bleed out on the surface of the pressure-sensitive adhesive layer at high temperatures, which may deteriorate the adhesive properties.

  The hydroxyl group-containing polyolefin (b) is not particularly limited, and examples thereof include polyethylene polyols, polypropylene polyols, polybutadiene polyols, hydrogenated polybutadiene polyols, polyisoprene polyols, and hydrogenated polyisoprene polyols. Among these, hydrogenated polyisoprene polyol, polyisoprene polyol, polybutadiene polyol, and hydrogenated polybutadiene polyol are preferable from the viewpoint of compatibility with the polyolefin (a).

  The hydroxyl value (mgKOH / g) of the hydroxyl group-containing polyolefin (b) is preferably 5 or more from the viewpoint of the strength of the pressure-sensitive adhesive layer, and is 95 or less from the viewpoint of the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer. Preferably there is. The hydroxyl value (mgKOH / g) of the hydroxyl group-containing polyolefin (b) is more preferably 10-80.

  A commercially available product can be used as the hydroxyl group-containing polyolefin (b). Examples of such commercially available products include Poly bd R-45HT (liquid polybutadiene having a hydroxyl group at the terminal, number average molecular weight 2800, hydroxyl value 46.6 mgKOH / g, manufactured by Idemitsu Kosan Co., Ltd.), Poly ip (with a hydroxyl group at the terminal). Liquid polyisoprene, number average molecular weight 2500, hydroxyl value 46.6 mg KOH / g, manufactured by Idemitsu Kosan Co., Ltd., Epol (liquid hydrogenated polyisoprene having a hydroxyl group at the terminal, number average molecular weight 2500, hydroxyl value 50.5 mg KOH / g , Manufactured by Idemitsu Kosan Co., Ltd.), GI-1000 (liquid polybutadiene having a hydroxyl group, number average molecular weight 1500, hydroxyl value 60-75 mg KOH / g, manufactured by Nippon Soda Co., Ltd.), GI-2000 (liquid hydrogenated polybutadiene having a hydroxyl group, number Average molecular weight 2100, hydroxyl value 40-55mgKOH / g, Nippon Soda GI-3000 (liquid polybutadiene having a hydroxyl group, number average molecular weight 3000, hydroxyl value 25 to 35 mg KOH / g, manufactured by Nippon Soda Co., Ltd.), Unistor P-801 (hydroxyl group-containing polyolefin, number average molecular weight 5000 or more, hydroxyl value) 40 mgKOH / g, manufactured by Mitsui Chemicals), Unistor P-901 (hydroxyl group-containing polyolefin, number average molecular weight 5000 or more, hydroxyl value 50 mgKOH / g, manufactured by Mitsui Chemicals).

The content of the hydroxyl group-containing polyolefin (b) in the pressure-sensitive adhesive is such that the A value in the following formula (I) is preferably 0.25 to 14250, more preferably 0.5 to 12000, and still more preferably 1 to 2500. Is set as follows.
A = hydroxyl value of the hydroxyl group-containing polyolefin (b) (mgKOH / g) × number of parts by weight of the hydroxyl group-containing polyolefin (b) with respect to 100 parts by weight of the polyolefin (a) (I)
If the A value is smaller than 0.25, the strength of the pressure-sensitive adhesive layer tends to be insufficient, and if larger than 14250, the pressure-sensitive adhesive force tends to decrease.

[Crosslinking agent (c)]
The pressure-sensitive adhesive of the present invention contains one or more cross-linking agents (c). The crosslinking agent (c) is used for reacting with the hydroxyl group-containing polyolefin (b) when forming the pressure-sensitive adhesive layer. Therefore, the crosslinking agent (c) has a functional group that can react with a hydroxyl group. Examples of the functional group capable of reacting with a hydroxyl group include an isocyanate group (also referred to as an isocyanato group) and a carboxy group. From the viewpoint of reactivity, the functional group capable of reacting with a hydroxyl group is preferably an isocyanate group. That is, the crosslinking agent (c) is preferably an isocyanate.

  The isocyanate may be either an aromatic isocyanate or an aliphatic isocyanate. The isocyanate is preferably an aromatic isocyanate.

  From the viewpoint of the strength of the pressure-sensitive adhesive layer, the isocyanate is preferably a polyisocyanate having 3 or more isocyanate groups in one molecule, more preferably at least selected from the group consisting of aromatic polyisocyanates and aliphatic polyisocyanates. It is at least one selected from the group consisting of a polyhydric alcohol adduct of an aromatic diisocyanate and a polyhydric alcohol adduct of an aliphatic diisocyanate.

  Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, and the like. Among these, tolylene diisocyanate is preferable from the viewpoint of reactivity and anchoring property of the obtained pressure-sensitive adhesive layer.

  Examples of the aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, isophorone diisocyanate, Examples thereof include cyclohexyl diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylene diisocyanate. Among these, 1,6-hexamethylene diisocyanate is preferable from the viewpoint of reactivity and anchoring property of the resulting pressure-sensitive adhesive layer.

  Examples of the polyhydric alcohol include aliphatic polyhydric alcohols such as ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, ditrimethylolpropane, and dipentaerythritol. Of these, trimethylolpropane is preferred.

  Examples of the polyisocyanate include a compound containing an isocyanate group at a terminal obtained by reacting the polyhydric alcohol with an excess amount of the diisocyanate.

  The content of the crosslinking agent (c) is preferably 0.01 to 150 parts by weight, more preferably 0.01 to 20 parts by weight, and still more preferably 0.05 to 100 parts by weight of the polyolefin (a). -10 parts by weight. When the content is less than 0.01 parts by weight, the anchoring property of the pressure-sensitive adhesive layer (that is, the adhesion to the substrate) may be lowered. On the other hand, when the content exceeds 150 parts by weight, the pressure-sensitive adhesive solution There may be adverse effects such as shortening the pot life or decreasing the adhesiveness of the adhesive layer (that is, the adhesiveness to the adherend).

[Optional ingredients]
The pressure-sensitive adhesive of the present invention may contain one or more optional components. Examples of the optional component include a urethanization catalyst for promoting the reaction between the hydroxyl group-containing polyolefin (b) and the isocyanate (that is, the crosslinking agent (c)).

  The pressure-sensitive adhesive of the present invention may contain one or more urethanization catalysts. Examples of the urethanization catalyst include tin compounds such as dibutyltin dilaurate and dioctyltin dilaurate, metal carboxylates such as zinc, cobalt, copper and bismuth, and 1,4-diazabicyclo [2.2.2] octane. Examples include amine compounds, chelate compounds of metals such as iron, titanium, and zirconium. In addition, bismuth organic acid salts (alicyclic organic acids such as abietic acid, neoabietic acid, d-pimalic acid, iso-d-pimalic acid, podocarpic acid, and bismuth resin acid containing two or more of these as a main component And bismuth salts of aromatic organic acids such as benzoic acid, cinnamic acid, and p-oxycinnamic acid. Among these, iron chelate compounds, dibutyltin dilaurate, dioctyltin dilaurate, and resin acid bismuth salt are preferable in terms of compatibility with pressure-sensitive adhesives and urethanization reaction, and iron chelate compounds are more preferable in terms of reactivity. preferable.

  The content of the urethanization catalyst is preferably 0.001 to 2.0 parts by weight, more preferably 0.005 to 1.5 parts by weight, and still more preferably 0.008 to 100 parts by weight of the polyolefin (a). -1.0 part by weight. If the content is less than 0.001 part by weight, the effect as a catalyst may not be sufficiently exhibited. On the other hand, when the content exceeds 2.0 parts by weight, there may be a problem that the pot life of the adhesive solution is shortened. In addition, content of a catalyst here refers to the quantity of only a catalyst (namely, active ingredient), for example, when using a commercially available catalyst solution, the quantity of only the catalyst except the amount of solvent is meant.

  The pressure-sensitive adhesive of the present invention may be a light stabilizer such as a resin other than the polyolefin (a) and the hydroxyl group-containing polyolefin (b), an antioxidant, an ultraviolet absorber, a hindered amine light stabilizer, or an antistatic agent, if necessary. Carbon black, calcium oxide, magnesium oxide, silica, zinc oxide, titanium oxide and other fillers, pigments and the like may be contained.

2. Adhesive Tape The present invention also provides an adhesive tape having a substrate and an adhesive layer. The pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive of the present invention on at least one side of the substrate. Hereinafter, a base material and an adhesive layer are demonstrated in order.

[Base material]
In the present invention, the substrate is not particularly limited. However, the substrate is preferably a plastic film having a smooth surface. Examples of the plastic film include polyester films such as polyethylene terephthalate film and polybutylene terephthalate film; polyolefin films such as polyethylene film and polypropylene film. Further, paper such as kraft paper, glassine paper, and high-quality paper may be used as the base material. As the paper substrate, in order to prevent excessive impregnation of the pressure-sensitive adhesive into the substrate, one obtained by laminating a plastic such as polyethylene or one subjected to sealing treatment is preferable. The base material may be subjected to a treatment such as a corona treatment, a plasma treatment, or a flame treatment in advance as necessary.

  The thickness in particular of a base material is not restrict | limited, It can set suitably according to a use purpose. When using a plastic film as a base material, the thickness is about 12-250 micrometers normally, Preferably it is 16-200 micrometers, More preferably, it is 25-125 micrometers.

  In addition, if necessary, light stabilizers such as antioxidants, ultraviolet absorbers, hindered amine light stabilizers and antistatic agents, carbon black, calcium oxide, magnesium oxide, silica, zinc oxide, titanium oxide fillers, You may mix | blend a pigment etc. with a base material.

[Adhesive layer]
The pressure-sensitive adhesive layer can be formed, for example, by dissolving the above-mentioned pressure-sensitive adhesive component in a solvent to obtain a pressure-sensitive adhesive solution, applying the obtained pressure-sensitive adhesive solution to a substrate, and drying. Although the solid content of an adhesive solution is not specifically limited in this invention, Usually, it exists in the range of 5 to 50 weight%.

  The solvent is not particularly limited as long as it can dissolve the pressure-sensitive adhesive component uniformly. However, since the pressure-sensitive adhesive of the present invention contains polyolefin (a), the solvent is preferably only one hydrocarbon solvent, a mixed solvent of two or more hydrocarbon solvents, or a hydrocarbon solvent. It is a mixed solvent with other solvents. When the mixed solvent is used, the content of the hydrocarbon solvent is preferably 50% by weight or more, more preferably 70% by weight or more, and more preferably 90% by weight or more in the mixed solvent. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as normal hexane and normal heptane, alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as toluene and xylene. Examples of other solvents include ketones such as methyl ethyl ketone, cyclohexanone and acetylacetone, esters such as ethyl acetate, alcohols such as methanol, ethanol and isopropyl alcohol.

  The method for applying the adhesive solution is not particularly limited, and any known method, for example, a method using a kiss roll coater, a bead coater, a rod coater, a Meyer bar coater, a die coater, a gravure coater or the like can be used. There is no particular limitation on the drying method, and any known method can be used. A common drying method is hot air drying. Although the temperature of hot-air drying can change also with the heat resistance of a base material, it is about 60-150 degreeC normally.

  The thickness (that is, the thickness after drying) of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive tape is preferably 1 to 100 μm, more preferably 2 to 80 μm, and still more preferably 3 to 60 μm. When the thickness is less than 1 μm, the tackiness (that is, the adhesiveness of the pressure-sensitive adhesive layer to the adherend) may be insufficient. On the other hand, when the thickness exceeds 100 μm, cohesive failure occurs in the pressure-sensitive adhesive layer when the tape is peeled off from the adherend, and adhesive residue may be generated on the adherend.

  The pressure-sensitive adhesive tape of the present invention may have a release agent layer in order to protect the pressure-sensitive adhesive layer. For example, the pressure-sensitive adhesive tape of the present invention may have a release agent layer on the substrate opposite to the pressure-sensitive adhesive layer (that is, “adhesive layer / substrate / release agent layer”). . In such a configuration, the release agent layer may be referred to as a back treatment layer, and the adhesive tape may be referred to as a back treatment layer-attached adhesive tape.

  Moreover, in order to protect the adhesive layer of the adhesive tape of this invention, you may use the mold release material in which the peeling agent layer was formed on the base material. Specifically, the pressure-sensitive adhesive layer may be protected by bringing the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape of the present invention into contact with the release agent layer of the release material (that is, “base material of pressure-sensitive adhesive tape / pressure-sensitive adhesive layer / Configuration of “Release Agent Layer / Releasing Material Base”). The pressure-sensitive adhesive tape having such a configuration is sometimes referred to as a pressure-sensitive adhesive tape with a release material.

  The pressure-sensitive adhesive tape of the present invention may have either a form in which a long tape is wound in a roll shape or a form in which a long tape is cut into an appropriate size and the cut tapes are stacked.

3. Physical properties, properties, etc. The physical properties, properties, etc. in this specification are measured values by the following methods.
(1) Number average molecular weight It is the value measured based on ASTM D2503.
(2) Hydroxyl value This is a value measured according to JIS K1557: 1970.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but these do not limit the present invention. In the following, “parts” and “%” represent “parts by weight” and “% by weight”, respectively, unless otherwise specified.

[Preparation of adhesive solution]
Each component was mixed in the number of parts shown in Tables 1 and 2, and this was dissolved in toluene to prepare an adhesive solution having a solid content of 15%. In addition, the solvent is not included in the number of parts of each component shown in Tables 1 and 2. That is, when the obtained component is a solution, the number of parts shown in Tables 1 and 2 represents the number of parts of the component itself (solid content) contained in the solution. Tables 1 and 2 list the A values in the above formula (I).

The meaning of the abbreviation of each component in Tables 1 and 2 is as follows.
(1) Polyolefin (a)
B80: “OPanol B80” manufactured by BASF Japan Ltd. (polyisobutylene, number average molecular weight 180,000)
B12: “Opanol B12” manufactured by BASF Japan (polyisobutylene, number average molecular weight 13,000)
app: “Tufselen H5002” manufactured by Sumitomo Chemical Co., Ltd. (amorphous copolymer of propylene / 1-butene)
(2) Hydroxyl-containing polyolefin (b)
Epole: “Epol” manufactured by Idemitsu Kosan Co., Ltd. (liquid hydrogenated polyisoprene having a hydroxyl group at the terminal, number average molecular weight 2500, hydroxyl value 50.5 mg KOH / g)
Poly ip: “Poly ip” manufactured by Idemitsu Kosan Co., Ltd. (liquid polyisoprene having a hydroxyl group at the terminal, number average molecular weight 2500, hydroxyl value 46.6 mgKOH / g)
GI3000: “GI-3000” manufactured by Nippon Soda Co., Ltd. (hydrogenated polybutadiene having a hydroxyl group at the terminal, number average molecular weight of about 3000, hydroxyl value of 25 to 35 mgKOH / g)
Unistor: “Unistor P-901” manufactured by Mitsui Chemicals (22% toluene solution of hydroxyl group-containing polyolefin, solid toluene, number average molecular weight of hydroxyl group-containing polyolefin> 5000, hydroxyl value 50 mgKOH / g)
(3) Crosslinking agent (c)
C / L: “Coronate L” manufactured by Nippon Polyurethane Co., Ltd. (75% ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate, number of isocyanate groups in one molecule: 3)
C / HL: “Coronate HL” manufactured by Nippon Polyurethane Co., Ltd. (75% ethyl acetate solution of trimethylolpropane adduct of hexamethylene diisocyanate, number of isocyanate groups in one molecule: 3)
(4) Urethane catalyst DBTDL: “Dibutyltin dilaurate (IV)” manufactured by Wako Pure Chemical Industries, Ltd. (dibutyltin dilaurate)
_{Fe (C 5 H 7 O 2} ) 3: Nihon Kagaku Sangyo Co., Ltd., "Nasemu ferric" (iron chelate)

[Preparation of adhesive tape (formation of adhesive layer)]
The prepared adhesive solution was applied to the substrates described in Tables 1 and 2 using a Baker type applicator, and then heated with a hot air dryer at 80 ° C. for 2 minutes to obtain an adhesive tape. Tables 1 and 2 show the thickness of the pressure-sensitive adhesive layer of the obtained pressure-sensitive adhesive tape.

The meanings of the abbreviations of the base materials in Tables 1 and 2 are as follows.
(1) PET
“Lumirror S10” manufactured by Toray Industries, Inc. (polyethylene terephthalate film, thickness 25 μm)
(2) OPP Corona “Trephan BO2548” manufactured by Toray Industries, Inc. (biaxially stretched polypropylene film with corona discharge treatment on both sides, thickness 30 μm)
(3) PP / PE corona Polypropylene / linear low density polyethylene film (thickness: 35 μm) prepared as follows and subjected to corona discharge treatment on both sides

[Preparation of PP / PE corona]
A molding material containing 80 parts of polypropylene (“Novatech PP FY4” manufactured by Nippon Polypro Co., Ltd.) and 20 parts of linear low density polyethylene (“Kernel KF380” manufactured by Nippon Polyethylene Co., Ltd.) is melt-kneaded with a film molding machine, and then molded. A polypropylene / linear low density polyethylene film was prepared by extruding from a machine T die. A corona discharge treatment is applied to both surfaces of this film, and a release agent layer (thickness: about 0.05 μm) is used on the surface (back surface) opposite to the surface on which the pressure-sensitive adhesive layer is formed using a long-chain alkyl release agent. ) Was formed.

[Evaluation of adhesive tape]
The anchoring property (that is, the adhesive property between the adhesive layer and the substrate) and the adhesive property (that is, the adhesive property between the adhesive layer and the adherend) of the obtained adhesive tape were evaluated as follows.

(1) Evaluation of anchoring property A SUS board was attached to the base material of the adhesive tape cut to 20 mm width with a double-sided tape, and the adhesive tape was lined. Nitto Denko Co., Ltd. “No. 315 tape” (rubber adhesive, 19 mm width) paste surface was combined with the adhesive layer of this adhesive tape, and the sample adhesive tape and 315 tape was attached. At this time, a paper sheet was put between these tapes. Load the addressed paper with a chuck and use a tensile tester to The base material and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape were peeled off by pulling the 315 tape in the 180 ° direction at a speed of 100 m / min. The force necessary for peeling (that is, the anchoring force necessary for peeling the substrate and the pressure-sensitive adhesive layer) was measured. The results are shown in Table 3. Moreover, the outline of the method of peeling the adhesive layer and base material of an adhesive tape is shown in FIG.

About the peeling form of the pressure-sensitive adhesive layer and the base material, the surface of the pressure-sensitive adhesive tape base material after the pressure-sensitive adhesive layer was peeled and the touch of the pressure-sensitive adhesive was present (that is, the pressure-sensitive adhesive layer was the base material upon peeling The material that remained on the surface was judged as “cohesive failure”, and the material that had only the feel of the base material (that is, the adhesive layer was all peeled off) was judged as “throwing failure”. The results are shown in Table 3.
Moreover, in the adhesive tape of an Example, there exist some which the base material cut | run_out at the time of peeling with an adhesive layer and a base material, and these were described as "Substrate run out" in Table 3.

(2) Evaluation of adhesiveness Adhesive tape cut to 10 mm x 100 mm was bonded to an adherend (SUS304 plate), and pressure-bonded by reciprocating a 2 kg roller from above. The pressure-sensitive adhesive tape pressure-bonded to the adherend was left for 20 to 40 minutes at a temperature of 23 ° C. in an air atmosphere at a temperature of 23 ° C. Next, using a tensile tester, the force necessary for peeling the adhesive tape from the adherend (ie, by pulling the adhesive tape at a speed of 300 mm / min in the direction of 180 ° in an air atmosphere at a temperature of 23 ° C. (ie, , Adhesive strength). The results are shown in Table 3.

  As shown in Table 3, in the pressure-sensitive adhesive tapes of Examples 1 to 16, the peeling form between the base material and the pressure-sensitive adhesive layer is “cohesive failure” or “base material break”. From these results, it can be seen that in the pressure-sensitive adhesive tapes of Examples 1 to 16, the base material and the pressure-sensitive adhesive layer are well bonded, and the anchoring property is excellent. On the other hand, in the pressure-sensitive adhesive tapes of Comparative Examples 1 to 6 shown in Table 2, in the peeling between the base material and the pressure-sensitive adhesive layer, the anchoring failure in which the pressure-sensitive adhesive layer does not remain on the base material occurs, and it is understood that the anchoring property is poor. . From comparison of these Examples 1-16 and Comparative Examples 1-6, it turns out that the adhesive layer formed from the adhesive of this invention exhibits the outstanding anchoring property.

  The pressure-sensitive adhesive of the present invention can form a pressure-sensitive adhesive layer excellent in anchoring properties with a substrate. The pressure-sensitive adhesive tape provided with such a pressure-sensitive adhesive layer can be suitably used for various applications.

DESCRIPTION OF SYMBOLS 1 SUS board 2 Base material 3 Adhesive layer 4 Adhesive tape 5 "No.315 tape" by Nitto Denko Corporation
6 Addressed paper

Claims (7)

  A pressure-sensitive adhesive containing a polyolefin (a), a hydroxyl group-containing polyolefin (b), and a crosslinking agent (c) having a functional group capable of reacting with a hydroxyl group.   The pressure-sensitive adhesive according to claim 1, wherein the crosslinking agent (c) is an isocyanate.   The pressure-sensitive adhesive according to claim 1 or 2, wherein the content of the crosslinking agent (c) is 0.01 to 150 parts by weight with respect to 100 parts by weight of the polyolefin (a). The A value in following formula (I) is 0.25-14250, The adhesive as described in any one of Claims 1-3.
A = hydroxyl value of the hydroxyl group-containing polyolefin (b) (mgKOH / g) × number of parts by weight of the hydroxyl group-containing polyolefin (b) with respect to 100 parts by weight of the polyolefin (a) (I)   The pressure-sensitive adhesive according to any one of claims 1 to 4, wherein the polyolefin (a) is a polymer having a structural unit derived from at least one selected from the group consisting of propylene, butene, hexene and octene. An adhesive tape having a base material and an adhesive layer,
The adhesive tape which has the adhesive layer formed from the adhesive as described in any one of Claims 1-5 on the at least single side | surface of a base material.   The pressure-sensitive adhesive tape according to claim 6, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 100 μm.

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